Portable flame thrower



March 17, 1953 E. c. SKOUSGAARD PORTABLE FLAME THROWER Filed Sept. 14, 1950 IN vjz'u TO R Elmer C. Skousgoord BY Qw. Wm

Fig.3.

Patented Mar. 17, 1953 UNITED STATES PATENT OFFICE 4 Claims.

Generally speaking, the present invention relates to an improved flame thrower, and more particularly, to a novel, light, portable flame thrower, weed burner and flame sterilizer of the type adapted for killing weeds, sterilizing soil, disinfecting structures and buildings (such as barns, livestock buildings, pens, and the like), rock splitting, and a variety of other uses. It is portable and is intended to be manually carried in a manner whereby the flame will be directed toward the areas to be treated.

I am aware of the fact that several prior art flame throwers and weed burners have been developed and invented heretofore. However, all of such prior art flame throwers and weed burners known to me have certain major disadvantages. In order to clarify this, I will briefly describe the usual prior art flame thrower and weed burner structure. It usually comprises a portable pressure vessel or tank, which is provided with suitable pump means for pressurizing suitable vaporizable, inflammable liquid contained therein (usually a hydrocarbon, such as kerosene or the like) by pumping air into the pressure vessel above the top surface of the inflammable liquid. Usually, the pressure vessel is connected by a flexible tube or hose to a burner unit (usually of the coil or ring vapor generating type), which is provided with manual handle means whereby the burner can be selectively directed toward a region to be treated. Usually, such prior art tanks are provided with suitable harness means, whereby they can be supported across the back or shoulders of the user or operator of th flame thrower or weed burner while the operator directs the burner toward .a selected region by means of the manual handle. Also, usually such prior art tanks are cylindrical with at least one longitudinal seam along the side thereof and closed at opposite ends by horizontal welded heads (sometimes brazed or silver soldered).

Such constructions have a major disadvantage in that every time it is necessary to re-pressurize the tank by means of the hand pump, the tank must be removed from the back or shoulders of the operator or user of the flame thrower and placed upon the ground before the pump will be accessible for re-pressurizing operation. Since both of the operators hands will usually be employed in the pumping operation, it will be necessary to place the burner in a selected safe spot prior to the pumping operation and hope that it will stay there during the pumping operation. Frequently, the burner may become dislodged from such a selected safe position during the 2 pumping operation because of motion imparted thereto through the flexible tube. This may lead to unpleasant, dangerous, or even disastrous results.

Another disadvantage of such prior art flame thrower and weed burner constructions is the fact that the welded (or brazed or silver soldered) construction (both along the tube and around the junctions of the heads with respect to the tube) provide flaws in overall strength of the pressure vessel, which may lead to failure thereof with consequent danger of property damage or personal injury to the operator or persons nearby. This inherent weakness of such prior art constructions has made it necessary to employ pressure gauges for the purpose of indicating when a maximum safe pressure has been reached. The pressure gauge thus adds unnecessarily to the cost of the entire unit.

Generally speaking, the light portable flame thrower of the present invention is so arranged as to be capable of being manually carried in the hands (no-t slung across the shoulders or back) during use, and is provided with means for supporting it in a convenient, accessible, upstanding, pumping position when not being manually carried and for fixedly supporting the burner means in a selected safe position with respect to the flame thrower when in the upstanding supported position. Generally speaking, it includes longitudinal, hollow, pressure vessel tank means adapted to contain a pressurized, vaporizable, inflammable liquid therein. Manually actuat'able pump means is carried by the tank means adjacent one end thereof in pumping relationship with respect thereto, whereby the interior of the tank means and the inflammable liquid adapted to be contained therein can be pressurized. Also provided is burner means including vapor generating means and air aspirating nozzle means adapted to emit a vaporized jet of inflammable liquid and mix same with an optimum quantity of ambient air to provide a mixed jet of optimum combustibility. Conduit means communicates the tank means and the burner means. Manually controllable valve means is arranged to control the now of the inflammable liquid through the conduit means to the burner means. The burner means is rigidly mounted in an angularly outwardly projecting direction with respect to the longitudinal axis of the tank means adjacent the end thereof opposite the pump carrying end of said tank means. Support means is carried by the tank means and projects outwardly and downwardly therefrom adjacent the end thereof,

carrying the burner means, and is arranged to support the longitudinal tank means in an upstanding position on a virtually flat surface with the burner means virtually laterally directed and with the side thereof virtually in contact with said flat surface. The arrangement being such that the pressure vessel will be in an upstanding position and the pump means adjacent the upper end thereof will be readily accessible for repressurizing the tank means and the inflammable liquid adapted to be contained therein.

In one general form of the present invention, means may be provided for removably mounting the pump means with respect to the end of the pressure vessel or tank carrying said pump means, whereby said pump means can be removed to allow the re-charging of the pressure vessel or tank with an inflammable liquid.

In one preferred general form of the present invention, the tank means is provided with longitudinal handle means fixedly mounted with respect thereto and provided with a longitudinal grasping member positioned virtually at right angles to the laterally directed burner means, whereby the burner means can be supported in a selected, virtually laterally directed position at any selected height above the ground by differ ent operators of different heights and lengths of arm by manually grasping the longitudinal rasping member at the proper point or points and can also be easily sup-ported (and directionally controlled) in a generally vertically directed position (or any other selected position).

In one general form of the present invention, the, longitudinal tank means may take the form of a hollow, longitudinal, cylindrical pressure vessel provided with spun ends, whereby maximum strength and minimum Weight will be attained.

From the above general description of the present invention, it will be understood that virtually all of the hereinabove mentioned disadvantages of prior art flame thrower and weed burner constructions are completely eliminated in the present invention. For example, the flame thrower of the present invention does not have to be slung across the shoulders or back in the manner of prior art flamethrowers, and since the burner means of the present invention is rigidly fixed with-respect to, and connected to the tank means in a selected safe position, it is not necessary to worry about finding a safe place to put the burner during the re-charg-ing or re-pressurizing operation, as was true of prior art constructions.

The flame thrower of the present invention can be manually held by means of the novel handle of the present invention in any selected position with respect to a region to be treated, and Whenever, for any reason whatsoever, the operator wishes. to place the flame thrower on the ground, all he has to do is place the support means on the ground and the under side of the laterally directed burner means on the ground. This will firmly support the entire flame thrower with respect to the ground with the upper end of the flame thrower tank in a convenient, accessible position for re-pressurizing interior of the tank by means of the pump carried thereon (which is also preferably, though not necessarily, removable for re-charging the tank). With this stable support arrangement for the flame thrower when not being manually carried, there is no chance that the burner will move with respect to the tank and possibly set fire to or otherwise damage adjacent regions, as was 4 frequently the case with prior art flame throwei= constructions, wherein the burner was flexibly, non-rigidly connected to the harness tank adapted to be carried across the shoulders or back of the operator.

Furthermore, the cylindrical seamless steel spun end construction of the tank of the preferred form of the present invention is considerably stronger (and lighter) than the hereinabove mentioned prior art constructions, and makes it possible to eliminate the pressure gauge which most prior art flame throwers have required in order to limit the pressure buildup therein to safe values to eliminate the possibility of failure because of the weak construction thereof.

It should also be noted that the handle of the present invention is so arranged as to make it possible for operators of different heights to utilize the flame thrower of the present invention withthe greatest possible efficiency andwith perfect balance, virtually irrespective of whether or not the flame thrower tank is full, virtually. empty, or at any level therebetween and virtually irrespective of the height of the operator.

Other and allied objects and advantages of the present invention will be. apparent to those skilled in the art after a careful perusal, examination and study of the illustrations, specification and appended claims.

To facilitate understanding, reference will be made to the hereinbelow described drawings, in which:

Fig. l is a side elevation of one illustrative embodiment of the present invention shown in upstanding supported. position such as it. would assume when not being manually carried during use.

Fig. 2 is an end elevation of the form of the present invention shown in Fig. 1, as viewed from the left of Fig. 1.

Fig. 3 is a fragmentary view, partially in vertical section of'the burner shown in Figs. 1 and 2, viewed from an aspect similar to. that of Fig. 1.

Generally speaking, the light, portable flame thrower of the present invention includes longitudinal, hollow, pressure vessel, tank. means adapted to contain a, pressurized, vaporizable, inflammable liquid therein. In the specific form of the present invention illustrated in the figures, the longitudinal, hollow, pressure vessel, tank takes the form of, a longitudinal, hollow, cylindrical, pressure vessel I. (preferably, though not necessarily, made from seamless steel tube). provided with spun ends, as indicated at 2. and. 3 This construction is extremely strong and light and makes it possible to eliminate the pressure gauge customarily required in prior art structures because of the weak construction thereof. It should be noted in passing that the. preferred, pressurized, vaporizable, inflammable liquid adapted to be contained in the torch is kerosene (or any other inflammable. liquid. of. generally similar characteristics), although. the present invention is not limited to the use of an inflammable hydrocarbon having generally similar characteristics to kerosene, but may em.- ploy a number of other inflammable liquids adapted to be pressurized in thetank.

Generally speaking, manually actuatable pump means is carried by thetank means adjacent one end thereof and in pumping rela tionship with respect to the hollow interior there.- of for pressurizing said vaporizable, inflammable liquidadaptedto be contained therein. In the specific example described andillustrated herein, the pump means is indicated generally at 4 and is mounted (preferably threadedly) so as to sealingly extend through an aperture or hole in the upper end 2 of the tank I downwardly into the interior of the upper end of the tank, in pumping relationship with respect thereto. In the specific example shown, the pump 4 is provided with a manual actuating handle 5, which can be manually actuated for pumping air into the interior of the tank I above the level of the kerosene (or other inflammable liquid) contained therein for suitably pressurizing same.

Generally speaking, the present invention includes burner means provided with vapor generating means and air aspirating nozzle means adapted to emit a vaporized jet of the inflammable liquid and mix same with an optimum quantity of aspirated ambient air to provide a mixed jet of optimum combustibility. Also generally speaking, conduit means is provided communicating the tank means and the burner means, and manually controllable valve means is arranged to control the flow of the inflammable liquid through the conduit means to the burner means.

In the specific example described and illustrated herein, the burner means is indicated generally at 6 and is effectively connected by conduit means I through a manually controllable valve means 8 to the interior of the tank I. In the specific example illustrated, the actual connection of the valve means 8 with respect to the interior of the tank I is by means of small inlet tube 9 which sealingly enters the interior of the tank I through a small hole or aperture in the bottom end 3 of the tank I in a manner whereby the open end of tube 9 will be submerged in the liquid fuel in the tank I even when the tank I is almost empty. This is true irrespective of whether the tank I is vertically positioned (as shown) or horizontally positioned (with handle I'I up) or in virtually any position therebetween. The burner B, conduit I and valve 8 are rigidly mounted in an angularly, outwardly projecting direction with respect to the longitudinal axis of the tank means I in a position such that the under side of the burner means will be virtually parallel to, and virtually in contact with, any flat supporting surface, such as is indicated generally at I0, when the flame thrower is in the upstanding, non-use position shown in Figs. 1 and 2.

Also generally speaking, the present invention is provided with support means carried by the tank means and projecting outwardly and downwardly therefrom, adjacent the end thereof carrying the burner means, and arranged to support the longitudinal tank means in a virtually upstanding position on a flat surface with the burner means virtually laterally directed and virtually in lateral contact with said fiat surface, whereby the pump means 4 will be in an upstanding, readily accessible position for re-pressurizing the tank means and the inflammable liquid adapted to be contained therein.

In the specific example described and illustrated herein, the support means comprises two spaced supporting brackets II and I2. Corresponding ends of each of the support brackets II and I2 are welded or otherwise suitably fastened to the longitudinal tank member I, as indicated at I3. The other ends of each of the support brackets II and I2 are divergingly, outwardly and downwardly directed and sharply bent back. so as to provide support feet It and I5 respectively, and the bent back ends are suitably fastened, such as by. welding to the lower end 3 of the tank I, as indicated at I6. It should be noted that the support feet I4 and I5 are positioned on the opposite sides of the longitudinal axis of the tank I from the burner means 6; whereby an effective 3-point support is provided for the entire flame thrower, and it is supported in the position shown in Figs. 1 and 2 in a very stable manner. It should also be noted that in the supported position shown in Figs. 1 and 2,,

flame emitted from the left hand end of the burner 6, as viewed in Fig. 1, will be laterally directed above the surface of the ground, and. the entire flame thrower can be sopositioned.

that the area in which the flame is directed will contain nothing likely to be damaged by the Therefore, it will not be necessary to trollable valve means 8 when the flame throweris placed in the positions shown in Figs. 1 and 2. for any purpose.

If desired, the flame thrower can be repressurized in the position shown in Figs. 1 and 2, since the pump 4 and the pump handle 5 are in a very convenient accessible position for repressurizing. Also, if desired, the pump 5 can be threadedly disengaged with respect to the similarly threaded aperture in the upper end 2 of the tank I to allow re-charging or refilling of the tank I to the proper level (usually threefourths full) with a suitable inflammable liquid, such as kerosene or the like.

In a preferred general form of the present invention, longitudinal handle means is fixedly mounted with respect to the longitudinal tank means and is provided with a longitudinal grasping member positioned virtually at right angles to the direction of the burner means, whereby the burner means can be supported in a selected, virtually laterally directed position during use and at various selected heights above the ground by operators of different heights and different lengths of arms by manually grasping the longitudinal member at the proper point or points and whereby the burner means can be supported (and directionally controlled) in a generally vertically directed position (or any other selected position) without interrupting the flow of fuel through the tube 9 to the burner 6.

In the specific example described and illustrated, the handle means comprises a longitudinal grasping member I'I virtually perpendicular to the burner means '6 and connected by curved end portions I8 and I9 to the wall of the tank I adjacent the bottom 3 and the top 2 thereof respectively.

The burner means 6 is illustrated in greater detail in Fig. 3 and includes a vapor generating coil, indicated generally at 20, one end of which is connected to the conduit I and the other end of which is connected to a conduit 2| leading to a forwardly directed jet orifice or nozzle means 22 (usually threadedly removable) arranged to emit a pressurized jet of the inflammable fluid contained in the pressurized vessel (whether in particulate, atomized, solid form or in vapor form) and direct same forwardly through and in intimate contact with the vapor generating coil 20 and out the left hand open end of the burner.

It should be noted that the rear of the shell 24 is open providingsuitable air inlet means to 7 the region around-the nozzle 22, where the jet of inflammable fluid is emitted so as to facilitate the aspiration of ambient air into the jet emitted from the nozzle 22, whereby the inflammable fluid will be thoroughly mixed with an optimum quantity of air to impart maximum combustibility to the forwardly directed jet. It should be noted that the nozzle 22 will emit either a stream or spray of liquid kerosene or an atomized spray of non-vaporized kerosene if the kerosene has not been thoroughly preheated and efie-ctively converted from the liquid form to the vapor form by preheating in the vapor generator coil 29. Therefore, when starting the flame thrower of the present invention, it is customary to preheat the vapor generator coil 29 in any suitable manner. For example, a mall amount of the kerosene can be allowed to escape and to drop into the bottom of'the case 24 (or a small depression or auxiliary pan provided therein) in a position immediately below the coil it, or an asbestos wick can be caused to be impregnated with the kerosene and placed in juxtaposition to the vapor generating coil 20.

Then the controllable valve means 8 is turned off so that no further kerosene will be emitted by the nozzle 22. The accumulated quantity of liquid kerosene, either impregnating the asbestos Wick hereinabove mentioned or positioned in the case 24 below the vapor generating coil 2 is then ignited and is allowed to preheat the vapor generating coil 26. In a short time after the vapor generating coil 25 has become surficiently hot to cause the kerosene contained therein to be converted into vapor, the manually controllable valve means 8 is opened to allow a small quantity of said vaporized kerosene to be emitted from the nozzle 22 in a forwardly directed jet (which, of course, will aspirate a suitable quantity of ambient air for maximum combustibility), which will become ignited from the preheating flame and which will subsequently maintain the vapor generating coil 25] at a temperature sufficiently high'to supply any desired quantity of virtually completelyvaporized'keroe sene (or other inflammable liquid) to the nozzle means 22.

It should be noted that a port 23 is provided in the shell 2 toallow the insertion of a nozzle cleaning tool so that the orifice in the nozzle 22 canbe cleaned easily if and when it becomes dirty or clogged.

In the example described and illustrated, a removable bracket '25 is provided for the purpose of removably mounting the burner shell '24 as fully as if-specifically described and illus trated herein. For example, any suitable type of pump'means may be employed. It may be arranged in any desired-manner for rapid removal from engagement with respect to the tank to provide an inlet-into the tank for the purpose of re-charging and refilling the tank-withthe inflammable liquid. Or in certain cases the tank may be re-charged and refilled through separate and distinct inlet means positioned in any se-' lected location with respect to the tank or with respect to the connection of the conduit 1 and/ or controllable valve means 8 to the other end of the tank. The exact position of the pump means with respect to the tank may be modified considerably, providing that it is arranged in an upstanding accessible position for re-pressurizing operation when the flame thrower is in the supported position with respect to a flat supporting surface.

The exact construction, configuration shape and relative positioning of the controllable valve means 8 and conduit I communicating the interior of the tank and the burner means may be modified substantially from that described and illustrated herein. The exact construction, configuration and arrangement of the burner means may be modified substantially from that described and illustrated herein, providing that the burner means is arranged in a rigidly, outwardly angularly related position with respect to the longitudinal tank means whereby one of the principal advantages of the present invention is obtained. Also, various arrangements for rapidly and simply dismounting and/or disassembling the burner and/or parts thereof may be provided. The exact arrangement, structure, and configuration of the supporting means of the present invention and/orthe handle means of the present invention can be modified substantially from that specifically described and illustrated herein. In certain forms of the present invention, the specific handle means described and illustrated herein in detail may, under some circumstances, be eliminated, and other suitable handle means arranged in an accessible position. In certain forms of the present invention including the rigidly related, out- Wardly, angularly directed burnermeans and the novel support means of the present invention, all of which are arranged to'eifectively support theentire flamethrower in a convenient, up standing position for easy repressurizin g thereof, the spun end structure of the tank means may be modified substantially, or other structural arrangements may be provided.

It should be understood that the term upstanding, as used herein to describe the position of the tank when in the supported position, and the term lateral or laterally directed, as used herein to describe the position of the burner when the fiame thrower is in the supported position, are not to be taken in a limiting sense. Any position wherein one end of the tank is substantially higher than the other end-is an upstanding position, and any position of the burner wherein at least a portion of the burner or connecting conduit are horizontally spaced from the bottom end of the tank orthe support means is a lateral or laterally directed position.

The embodiments of the present invention described and illustrated herein are exemplary only and are not intended to limit the scope of the present invention which is to be interpreted in the light of the prior art and the appended claims only, with due consideration for the doctrine of equivalents.

Iclaim:

l. A light, portable fia'me throweradapted to be manually carried duringuse and provided with means for supporting it in a convenient, virtually upstanding position when not being manually carried, comprising: longitudinal, hollow, pressure vessel, tank means adapted to contain a pressurized, vaporizable, inflammable liquid therein; manually actuatable pump means carried by the tank means adjacent one end thereof, in pumping relationship with respect thereto, for pressurizing the interior of the tank means and the vaporizable, inflammable liquid adapted to be contained therein; burner means including vapor generating means and air aspirating nozzle means adapted to emit a vaporized jet of the inflammable liquid and mix same with an optimum quantity of ambient air to provide a mixed jet of optimum combustibility; conduit means communicating the tank means and the burner means; manually controllable valve means arranged to control the flow of the inflammable liquid through the conduit means to the burner means; said burner means being rigidly mounted in an angularly, outwardly projecting direction with respect to the longitudinal axis of the tank means adjacent the end thereof opposite the pump carrying end of said tank means; support means carried by the tank means and projecting outwardly and downwardly therefrom adjacent the end thereof carrying the burner means arranged to support the longitudinal tank means in an upstanding position on a flat surface with the burner means virtually laterally directed and virtually in contact with said fiat surface, whereby the pump means will be in an upstanding readily accessible position for re-pressurizing the tank means and the inflammable liquid adapted to be contained therein.

2. A device of the character defined in claim 1, wherein the support means comprises at least two outwardly and downwardly directed support brackets positioned on opposite sides of the longitudinal axis of the longitudinal tank means from the burner means laterally extending therefrom, whereby the laterally extending burner means and the two support brackets will firmly support the longitudinal tank means in an upstanding position when placed in contact with a virtually flat supporting surface.

3. A light portable flame thrower adapted to be manually carried during use and provided with means for supporting it in a convenient, virtually upstanding position when not being manually carried, comprising: longitudinal, hollow, pressure vessel, tank means adapted to contain a pressurized, vaporizable, inflammable liquid therein; manually actuatable pump means carried by the tank means adjacent one end thereof, in pumping relationship with respect thereto for pressurizing the interior of the tank means and the vaporizable, inflammable liquid adapted to be contained therein; burner means including vapor generating means and air aspirating nozzle 10 means adapted to emit a vaporized jet of the inflammable liquid and mix same with an optimum quantity of ambient air to provide a mixed jet of optimum combustibility; conduit means communieating the tank means and the burner means; manually controllable valve means arranged to control the flow of the inflammable liquid through the conduit means to the burner means; said burner means being rigidly mounted in an angularly, outwardly projecting direction with respect to the longitudinal axis of the tank means adjacent the end thereof opposite the pump carrying end of said tank means; support means carried by the tank means and projecting outwardly and downwardly therefrom adjacent the end thereof carrying the burner means arranged to support the longitudinal tank means in an upstanding position on a fiat surface with the burner means virtually laterally directed and virtually in contact with said flat surface, whereby the pump means will be in an upstanding readily accessible position for re-pressurizing the tank means and the inflammable liquid adapted to be contained therein; longitudinal handle means fixedly mounted with respect to the longitudinal tank means and provided with a longitudinal grasping member positioned virtually at right angles to the laterally directed burner means whereby the burner means can be supported in virtually any direction in balanced, fuel feeding position by manually grasping the longitudinal grasping member at the proper points.

4. A device of the character defined in claim 3, wherein the support means comprises at least two outwardly and downwardly directed support brackets positioned on opposite sides of the longitudinal axis of the longitudinal tank means from the burner means laterally extending therefrom whereby the laterally extending burner means and the two support brackets will firmly support the longitudinal tank means in an upstanding position when placed in contact with a flat supporting surface.

ELMER C. SKOUSGAARD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 623,374 Johnson Apr. 18, 1899 1,014,113 Binkley Jan. 9, 1912 1,074,374 Messerli Sept. 30, 1913 1,189,683 Greer July 4, 1916 1,254,145 Lieber Jan. 22, 1918 1,391,774 Gerstenberger Sept. 27, 1921 2,284,316 Glass May 26, 1942 2,494,720 Richards Jan. 17, 1950 

